I've been wanting to do this on a much smaller scale when I get a new computer (I start planning computer builds years before actually start building them). I set up a two disk stripe on my current one but since the mean time between failures for solid state drives is so much bigger than for platter drives you can confidently set up as large of a stripe as you can afford. With 24 cheap platter drives you'd get similar rediculous speeds (not as rediculous, but still) but the combined chance of failure for them would but pushing it.
For those of you who don't have esperience with this kind of thing, if any drive in a stripe dies the whole thing dies. Any single hard drive tends to last quite a while, but add enough and you suddenly get failures a little more often than most people would be comfortable risking.
Newegg currently sells a 16GB solid state drive for $75, 6 in a stripe would "only" be $450 and would have a theoretical maximum read of about 900MB/second. I wish the Samsung guys would have shown exactly how they have theirs set up though. They're probably using some tricks that would be nice to know.
Currently it is common to have 1 TB in an new computer, it doubles each 1 1/2 year, so in about 3 years this setup will be available for everyone
Not taking in account slower Windows editions
You're thinking of platter drives, these are solid state drives. By your equasion in 3 years solid state will be about 1GB/$1 which is still a rediculous amount when you can buy 10GB/$1 platter drives now.
Next will be the BIG Gaming industry too begin using this besides dvd's. Write protected of course!
Unlikely, hardrives are so much heavier than DVD's the shipping cost would skyrocket, and most people don't want to open their case and muck about in order to install a game.
